Major fixes and new features

venv/lib/python3.12/site-packages/asyncpg/pgproto/codecs/numeric.pyx

@@ -0,0 +1,356 @@
+# Copyright (C) 2016-present the asyncpg authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of asyncpg and is released under
+# the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
+
+
+from libc.math cimport abs, log10
+from libc.stdio cimport snprintf
+
+import decimal
+
+# defined in postgresql/src/backend/utils/adt/numeric.c
+DEF DEC_DIGITS = 4
+DEF MAX_DSCALE = 0x3FFF
+DEF NUMERIC_POS = 0x0000
+DEF NUMERIC_NEG = 0x4000
+DEF NUMERIC_NAN = 0xC000
+DEF NUMERIC_PINF = 0xD000
+DEF NUMERIC_NINF = 0xF000
+
+_Dec = decimal.Decimal
+
+
+cdef numeric_encode_text(CodecContext settings, WriteBuffer buf, obj):
+    text_encode(settings, buf, str(obj))
+
+
+cdef numeric_decode_text(CodecContext settings, FRBuffer *buf):
+    return _Dec(text_decode(settings, buf))
+
+
+cdef numeric_encode_binary(CodecContext settings, WriteBuffer buf, obj):
+    cdef:
+        object dec
+        object dt
+        int64_t exponent
+        int64_t i
+        int64_t j
+        tuple pydigits
+        int64_t num_pydigits
+        int16_t pgdigit
+        int64_t num_pgdigits
+        int16_t dscale
+        int64_t dweight
+        int64_t weight
+        uint16_t sign
+        int64_t padding_size = 0
+
+    if isinstance(obj, _Dec):
+        dec = obj
+    else:
+        dec = _Dec(obj)
+
+    dt = dec.as_tuple()
+
+    if dt.exponent == 'n' or dt.exponent == 'N':
+        # NaN
+        sign = NUMERIC_NAN
+        num_pgdigits = 0
+        weight = 0
+        dscale = 0
+    elif dt.exponent == 'F':
+        # Infinity
+        if dt.sign:
+            sign = NUMERIC_NINF
+        else:
+            sign = NUMERIC_PINF
+        num_pgdigits = 0
+        weight = 0
+        dscale = 0
+    else:
+        exponent = dt.exponent
+        if exponent < 0 and -exponent > MAX_DSCALE:
+            raise ValueError(
+                'cannot encode Decimal value into numeric: '
+                'exponent is too small')
+
+        if dt.sign:
+            sign = NUMERIC_NEG
+        else:
+            sign = NUMERIC_POS
+
+        pydigits = dt.digits
+        num_pydigits = len(pydigits)
+
+        dweight = num_pydigits + exponent - 1
+        if dweight >= 0:
+            weight = (dweight + DEC_DIGITS) // DEC_DIGITS - 1
+        else:
+            weight = -((-dweight - 1) // DEC_DIGITS + 1)
+
+        if weight > 2 ** 16 - 1:
+            raise ValueError(
+                    'cannot encode Decimal value into numeric: '
+                    'exponent is too large')
+
+        padding_size = \
+            (weight + 1) * DEC_DIGITS - (dweight + 1)
+        num_pgdigits = \
+            (num_pydigits + padding_size + DEC_DIGITS - 1) // DEC_DIGITS
+
+        if num_pgdigits > 2 ** 16 - 1:
+            raise ValueError(
+                    'cannot encode Decimal value into numeric: '
+                    'number of digits is too large')
+
+        # Pad decimal digits to provide room for correct Postgres
+        # digit alignment in the digit computation loop.
+        pydigits = (0,) * DEC_DIGITS + pydigits + (0,) * DEC_DIGITS
+
+        if exponent < 0:
+            if -exponent > MAX_DSCALE:
+                raise ValueError(
+                    'cannot encode Decimal value into numeric: '
+                    'exponent is too small')
+            dscale = <int16_t>-exponent
+        else:
+            dscale = 0
+
+    buf.write_int32(2 + 2 + 2 + 2 + 2 * <uint16_t>num_pgdigits)
+    buf.write_int16(<int16_t>num_pgdigits)
+    buf.write_int16(<int16_t>weight)
+    buf.write_int16(<int16_t>sign)
+    buf.write_int16(dscale)
+
+    j = DEC_DIGITS - padding_size
+
+    for i in range(num_pgdigits):
+        pgdigit = (pydigits[j] * 1000 + pydigits[j + 1] * 100 +
+                   pydigits[j + 2] * 10 + pydigits[j + 3])
+        j += DEC_DIGITS
+        buf.write_int16(pgdigit)
+
+
+# The decoding strategy here is to form a string representation of
+# the numeric var, as it is faster than passing an iterable of digits.
+# For this reason the below code is pure overhead and is ~25% slower
+# than the simple text decoder above.  That said, we need the binary
+# decoder to support binary COPY with numeric values.
+cdef numeric_decode_binary_ex(
+    CodecContext settings,
+    FRBuffer *buf,
+    bint trail_fract_zero,
+):
+    cdef:
+        uint16_t num_pgdigits = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
+        int16_t weight = hton.unpack_int16(frb_read(buf, 2))
+        uint16_t sign = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
+        uint16_t dscale = <uint16_t>hton.unpack_int16(frb_read(buf, 2))
+        int16_t pgdigit0
+        ssize_t i
+        int16_t pgdigit
+        object pydigits
+        ssize_t num_pydigits
+        ssize_t actual_num_pydigits
+        ssize_t buf_size
+        int64_t exponent
+        int64_t abs_exponent
+        ssize_t exponent_chars
+        ssize_t front_padding = 0
+        ssize_t num_fract_digits
+        ssize_t trailing_fract_zeros_adj
+        char smallbuf[_NUMERIC_DECODER_SMALLBUF_SIZE]
+        char *charbuf
+        char *bufptr
+        bint buf_allocated = False
+
+    if sign == NUMERIC_NAN:
+        # Not-a-number
+        return _Dec('NaN')
+    elif sign == NUMERIC_PINF:
+        # +Infinity
+        return _Dec('Infinity')
+    elif sign == NUMERIC_NINF:
+        # -Infinity
+        return _Dec('-Infinity')
+
+    if num_pgdigits == 0:
+        # Zero
+        return _Dec('0e-' + str(dscale))
+
+    pgdigit0 = hton.unpack_int16(frb_read(buf, 2))
+    if weight >= 0:
+        if pgdigit0 < 10:
+            front_padding = 3
+        elif pgdigit0 < 100:
+            front_padding = 2
+        elif pgdigit0 < 1000:
+            front_padding = 1
+
+    # The number of fractional decimal digits actually encoded in
+    # base-DEC_DEIGITS digits sent by Postgres.
+    num_fract_digits = (num_pgdigits - weight - 1) * DEC_DIGITS
+
+    # The trailing zero adjustment necessary to obtain exactly
+    # dscale number of fractional digits in output.  May be negative,
+    # which indicates that trailing zeros in the last input digit
+    # should be discarded.
+    trailing_fract_zeros_adj = dscale - num_fract_digits
+
+    # Maximum possible number of decimal digits in base 10.
+    # The actual number might be up to 3 digits smaller due to
+    # leading zeros in first input digit.
+    num_pydigits = num_pgdigits * DEC_DIGITS
+    if trailing_fract_zeros_adj > 0:
+        num_pydigits += trailing_fract_zeros_adj
+
+    # Exponent.
+    exponent = (weight + 1) * DEC_DIGITS - front_padding
+    abs_exponent = abs(exponent)
+    if abs_exponent != 0:
+        # Number of characters required to render absolute exponent value
+        # in decimal.
+        exponent_chars = <ssize_t>log10(<double>abs_exponent) + 1
+    else:
+        exponent_chars = 0
+
+    # Output buffer size.
+    buf_size = (
+        1 +                 # sign
+        1 +                 # leading zero
+        1 +                 # decimal dot
+        num_pydigits +      # digits
+        1 +                 # possible trailing zero padding
+        2 +                 # exponent indicator (E-,E+)
+        exponent_chars +    # exponent
+        1                   # null terminator char
+    )
+
+    if buf_size > _NUMERIC_DECODER_SMALLBUF_SIZE:
+        charbuf = <char *>cpython.PyMem_Malloc(<size_t>buf_size)
+        buf_allocated = True
+    else:
+        charbuf = smallbuf
+
+    try:
+        bufptr = charbuf
+
+        if sign == NUMERIC_NEG:
+            bufptr[0] = b'-'
+            bufptr += 1
+
+        bufptr[0] = b'0'
+        bufptr[1] = b'.'
+        bufptr += 2
+
+        if weight >= 0:
+            bufptr = _unpack_digit_stripping_lzeros(bufptr, pgdigit0)
+        else:
+            bufptr = _unpack_digit(bufptr, pgdigit0)
+
+        for i in range(1, num_pgdigits):
+            pgdigit = hton.unpack_int16(frb_read(buf, 2))
+            bufptr = _unpack_digit(bufptr, pgdigit)
+
+        if dscale:
+            if trailing_fract_zeros_adj > 0:
+                for i in range(trailing_fract_zeros_adj):
+                    bufptr[i] = <char>b'0'
+
+            # If display scale is _less_ than the number of rendered digits,
+            # trailing_fract_zeros_adj will be negative and this will strip
+            # the excess trailing zeros.
+            bufptr += trailing_fract_zeros_adj
+
+        if trail_fract_zero:
+            # Check if the number of rendered digits matches the exponent,
+            # and if so, add another trailing zero, so the result always
+            # appears with a decimal point.
+            actual_num_pydigits = bufptr - charbuf - 2
+            if sign == NUMERIC_NEG:
+                actual_num_pydigits -= 1
+
+            if actual_num_pydigits == abs_exponent:
+                bufptr[0] = <char>b'0'
+                bufptr += 1
+
+        if exponent != 0:
+            bufptr[0] = b'E'
+            if exponent < 0:
+                bufptr[1] = b'-'
+            else:
+                bufptr[1] = b'+'
+            bufptr += 2
+            snprintf(bufptr, <size_t>exponent_chars + 1, '%d',
+                     <int>abs_exponent)
+            bufptr += exponent_chars
+
+        bufptr[0] = 0
+
+        pydigits = cpythonx.PyUnicode_FromString(charbuf)
+
+        return _Dec(pydigits)
+
+    finally:
+        if buf_allocated:
+            cpython.PyMem_Free(charbuf)
+
+
+cdef numeric_decode_binary(CodecContext settings, FRBuffer *buf):
+    return numeric_decode_binary_ex(settings, buf, False)
+
+
+cdef inline char *_unpack_digit_stripping_lzeros(char *buf, int64_t pgdigit):
+    cdef:
+        int64_t d
+        bint significant
+
+    d = pgdigit // 1000
+    significant = (d > 0)
+    if significant:
+        pgdigit -= d * 1000
+        buf[0] = <char>(d + <int32_t>b'0')
+        buf += 1
+
+    d = pgdigit // 100
+    significant |= (d > 0)
+    if significant:
+        pgdigit -= d * 100
+        buf[0] = <char>(d + <int32_t>b'0')
+        buf += 1
+
+    d = pgdigit // 10
+    significant |= (d > 0)
+    if significant:
+        pgdigit -= d * 10
+        buf[0] = <char>(d + <int32_t>b'0')
+        buf += 1
+
+    buf[0] = <char>(pgdigit + <int32_t>b'0')
+    buf += 1
+
+    return buf
+
+
+cdef inline char *_unpack_digit(char *buf, int64_t pgdigit):
+    cdef:
+        int64_t d
+
+    d = pgdigit // 1000
+    pgdigit -= d * 1000
+    buf[0] = <char>(d + <int32_t>b'0')
+
+    d = pgdigit // 100
+    pgdigit -= d * 100
+    buf[1] = <char>(d + <int32_t>b'0')
+
+    d = pgdigit // 10
+    pgdigit -= d * 10
+    buf[2] = <char>(d + <int32_t>b'0')
+
+    buf[3] = <char>(pgdigit + <int32_t>b'0')
+    buf += 4
+
+    return buf